Blood-stage immunity to Plasmodium chabaudi malaria following chemoprophylaxis and sporozoite immunization
- MRC National Institute for Medical Research, United Kingdom
- Radboud University Medical Centre, Netherlands
Figures
Figure 1
Overview of experimental procedures.
To quantify transient blood-stage exposure during chemoprophylaxis and sporozoite (CPS) immunization female C57BL/6 were immunized three times at 2-week intervals with P. chabaudi AS-infected …
Figure 2
Chloroquine permits transient blood-stage parasitemia during each immunization.
The number of parasitized erythrocytes (pE) per ml of whole blood was enumerated by quantitative RealTime PCR after each CPS immunization (i1, i2, i3) with P. chabaudi AS-infected mosquito bites …
Figure 3
Pre-erythrocytic immunity following CPS immunization requires high doses of sporozoites.
Liver parasite burden was determined 42 hr after mosquito bite challenge as copy number of P. chabaudi-specific 18S rRNA. (A) Mice were CPS immunized three times (i1, i2, i3) with P. chabaudi …
Figure 4 with 1 supplement
CPS immunization elicits blood-stage immunity.
Mice were CPS immunized three times (i1, i2, i3) using chloroquine (CQ) and P. chabaudi AS-infected or uninfected mosquito bites (mock immunized). Approximately 100 days after the final CPS …
Figure 4—figure supplement 1
Chronic blood-stage infection in CPS immunized mice.
Naive infection controls or mice that were CPS immunized three times (i1, i2, i3) using chloroquine (CQ) and P. chabaudi AS-infected mosquito bites were challenged (C) by intraperitoneal (ip) …
Figure 5
CPS immunization elicits heterologous blood-stage immunity.
Mice were CPS immunized three times (i1, i2, i3) under chloroquine (CQ) cover by P. chabaudi AS-infected mosquito bites or mock immunized with uninfected mosquito bites, and challenged (C) 96–107 …
Figure 6
Extended blood-stage parasitemia elicits pre-erythrocytic immunity.
Mice received a first infection with P. chabaudi AS either by mosquito bite (Bite) or intraperitoneal (ip) injection of 10,000 parasitized erythrocytes obtained from a donor mouse infected by …
Tables
Table 1
Relationship between the dose of immunizing pre-erythrocytic and blood-stage parasites and the acquisition of immunity.
| Low dose | High dose | |
|---|---|---|
| Sporozoites (liver-stage parasites) | Mosquito bite or 100 sporozoites iv: no pre-erythrocytic immunity (Figure 3A/B) | 10,000 sporozoites iv: pre-erythrocytic immunity (Figure 3B) |
| Blood-stage parasites | Blood-stage infection curtailed by chloroquine: partial blood-stage immunity (Figure 4) | Fulminant, self-cured blood-stage infection: blood-stage immunity (Spence et al., 2013); pre-erythrocytic immunity (Figure 6) |
